Containerized freight and Air/truck

[Spinward Flow]

All that is useful to think about in terms of what grav brings- but there are a lot of TL 8- worlds out there and a need to service them.

Probably a two tier system, like the international's TEU and then the North American domestic 53 foot standard.

Starports are probably going to have gravitics tech for the marshaling of cargoes, regardless of world tech level, assuming type A-C starports.
Type D starports may be limited to world tech level logistics support options ... so if TL=7- then the use of gravitics for logistics marshaling within the starport itself shouldn't be assumed.
Type E-X starports ... by definition are "bring your own logistics" with respect to the marshaling of cargoes.

External to the starport, by all means ... world TL will govern what kinds of logistics network transport is available ... and if a world is TL=7- then "global" gravitics transport services should NOT be assumed. Therefore, the "local" logistics network is going to be based on the type of environment that world has.

Low gravity and thick atmosphere?
Lots of aero lift.

Desert world?
Road and rail transport.

No atmosphere on a barren world?
Expect to use rail transport between dome settlements.

Water world?
Plan for surface ship and/or submarine transport networks for heavy loads, maybe airlift for lighter loads.



When surface gravity, atmospheric pressure/composition and hydrographics percentages can all vary (widely!), the types and nature of the "optimal" form factors for local transportation will also vary widely ... especially when assuming that almost every populated world on the sector map needed to be colonized from a "homeworld" somewhere else on the map. Point being that LOCAL environmental factors may mean that standards on different worlds "don't fit right" for the conditions present HERE ... so the local world logistics network gets built out to a different standard than what would be present on other worlds.

Think about the environmental differences between Terra and Luna, for example.
There might be "different form factors" that the environment of Luna makes possible/preferable which would be entirely impractical (or at least, not backwards compatible) on Terra.

Once you reach TL=9+ and move into the interstellar transport realm of things, the "starship hold" form factor becomes something of a "common constraint" that you need to work within ... and at that point you've got gravitics, so might as well standardize on the form factors involved with THAT environment when it comes to starship construction and starport logistics standardization.

Your mileage may vary, of course.

 

[Rupert]

Containerization is basically bundling cargo in a simple and standardized manner.

Then you have ease of handling.

And, what's too small, and what's too large.

As I recall, a thousand tonnes was the largest amount mentioned in Classic.

Five tonnes is about a forty footer.

We have a crane that does sixty five tonnes.

By volume a 20-foot container is about 2.75 DTons (external volume), a 40-foot is about 5.5 DTons, and a 40-foot high-cube is about 6.25 DTons. Interior volumes are about 2.5, 5, and 5.5 Dtons, respectively. In all cases the standard maximum gross weight is just under 30.5 tonnes.

I find it interesting that the 40-foot containers are becoming more common, despite having the same maximum weight. It shows that we're shipping more and more stuff that's low in density.

 

[Condottiere]

Chicken and egg.

Does infrastructure determine cargo forms, or do cargo forms determine infrastructure?

Personally, I tend to think that pre existing infrastructure determine cargo forms, but that both evolve as efficiencies are identified, or something new is introduced

 

[Dragoner]

Tradition is important as well:

 

[whartung]

This is wonderful.

The singular problem with containerized freight is having the room to 8-puzzle the boxes into the holds.

The beauty of our modern system is that the ship is simply a vast, gaping hole in the water that containers are stacked into. With their open tops, it's straightforward using cranes to move and stack the containers efficiently.

Enclosed starships are another matter. Anyone who's loaded boxes into one of those self-storage places knows what I'm talking about.

The containers will not readily slide on each other. Modern containers are actually locked together.

You'll want a hold door to be as high as the containers can stack so that the moving equipment can place them properly. Not different than loading up semi-trailer. But with something like a free trader, only 80ish tons of space, that's 16 5 ton containers (and the classic spec FT is clearly not designed for the regular shapes of containers).

So, anyway, you just need large holds, with big doors to really accommodate containerized payloads. None of this folks with grav dollies walking up and down ramps.

 

[kilemall]

Starports are probably going to have gravitics tech for the marshaling of cargoes, regardless of world tech level, assuming type A-C starports.
Type D starports may be limited to world tech level logistics support options ... so if TL=7- then the use of gravitics for logistics marshaling within the starport itself shouldn't be assumed.
Type E-X starports ... by definition are "bring your own logistics" with respect to the marshaling of cargoes.

External to the starport, by all means ... world TL will govern what kinds of logistics network transport is available ... and if a world is TL=7- then "global" gravitics transport services should NOT be assumed. Therefore, the "local" logistics network is going to be based on the type of environment that world has.

Low gravity and thick atmosphere?
Lots of aero lift.

Desert world?
Road and rail transport.

No atmosphere on a barren world?
Expect to use rail transport between dome settlements.

Water world?
Plan for surface ship and/or submarine transport networks for heavy loads, maybe airlift for lighter loads.



When surface gravity, atmospheric pressure/composition and hydrographics percentages can all vary (widely!), the types and nature of the "optimal" form factors for local transportation will also vary widely ... especially when assuming that almost every populated world on the sector map needed to be colonized from a "homeworld" somewhere else on the map. Point being that LOCAL environmental factors may mean that standards on different worlds "don't fit right" for the conditions present HERE ... so the local world logistics network gets built out to a different standard than what would be present on other worlds.

Think about the environmental differences between Terra and Luna, for example.
There might be "different form factors" that the environment of Luna makes possible/preferable which would be entirely impractical (or at least, not backwards compatible) on Terra.

Once you reach TL=9+ and move into the interstellar transport realm of things, the "starship hold" form factor becomes something of a "common constraint" that you need to work within ... and at that point you've got gravitics, so might as well standardize on the form factors involved with THAT environment when it comes to starship construction and starport logistics standardization.

Your mileage may vary, of course.

The point of a container is load once unload once. So whatever combo, there would be a need for low tech baselines.

Grav advantage standards sure, but coexisting as much as possible.

 

[kilemall]

This is wonderful.

The singular problem with containerized freight is having the room to 8-puzzle the boxes into the holds.

The beauty of our modern system is that the ship is simply a vast, gaping hole in the water that containers are stacked into. With their open tops, it's straightforward using cranes to move and stack the containers efficiently.

Enclosed starships are another matter. Anyone who's loaded boxes into one of those self-storage places knows what I'm talking about.

The containers will not readily slide on each other. Modern containers are actually locked together.

You'll want a hold door to be as high as the containers can stack so that the moving equipment can place them properly. Not different than loading up semi-trailer. But with something like a free trader, only 80ish tons of space, that's 16 5 ton containers (and the classic spec FT is clearly not designed for the regular shapes of containers).

So, anyway, you just need large holds, with big doors to really accommodate containerized payloads. None of this folks with grav dollies walking up and down ramps.

Likely more like orbital exterior mounts. Very fast swaps for maximum utility of the big megaliners. ACS are another matter.

 

[Rupert]

Likely more like orbital exterior mounts. Very fast swaps for maximum utility of the big megaliners. ACS are another matter.

Of course this requires vacuum and open-space rated containers, and for many cargoes they'll need to be able to hold pressure for the week or ten days they'll be in space. Oh, and jump-space rated as well, with in many TUs means they'll need embedded jump grids, plus automated hookups for that, etc.

It might be easier to have what looks like exterior mounts down a long skinny ship's spine, but have massive clamshells that enclose everything once the ship is loaded. The way the containers only have to be rated for a few hours exposure to space, for the transit from the station's holds to the ship (or vice versa).

 

[Dragoner]

Strap it to the outside. Then have interface craft for delivery:

 

[Condottiere]

If you're using the lanthanum grid, drape a jump net over the exposed containers.

Otherwise, in a jump bubble, it doesn't matter, as long as everything is within it.

 

[Spinward Flow]

Chicken and egg.

Does infrastructure determine cargo forms, or do cargo forms determine infrastructure?

Depends on if you're dealing with a homeworld standardization or a colony transplant context.

If it's a homeworld situation, then the infrastructure probably came first and the cargo form factors come along later to standardize a "fit" into that infrastructure.

If you're doing a "clean slate" colonization of another world (interplanetary and/or interstellar) then the form factors come first and the infrastructure gets built out as needed to support the colonization effort. This is why I maintain that because gravitics are TL=8 and jump drives are TL=9 (at least in CT), that means that ANY colony presence is probably going to START with gravitics for its transport logistics.

Now, it's perfectly possible for a colony world to "regress" to lower tech levels, either voluntarily or involuntarily ... but every interstellar transplant starts at TL=9+ minimum, meaning gravitics are available. Every "new" colony project starts from No Infrastructure available when dealing with a "pristine" world environment ... so might as well "start with gravitics" from the beginning. Eventually, as the population increases (to 7+) you'll probably start seeing other means of logistics transport aside from just gravitics emerge, but that's a "later on down the line" development for a colony that has survived startup and is prospering in its build out.

The containers will not readily slide on each other. Modern containers are actually locked together.

You'll want a hold door to be as high as the containers can stack so that the moving equipment can place them properly. Not different than loading up semi-trailer. But with something like a free trader, only 80ish tons of space, that's 16 5 ton containers (and the classic spec FT is clearly not designed for the regular shapes of containers).

So, anyway, you just need large holds, with big doors to really accommodate containerized payloads. None of this folks with grav dollies walking up and down ramps.

Depends on what you stuff into your cargo hold(s).
If it's just "loose" breakbulk occupying space, you can get away with pallets for stuff and drive forklifts around (and up/down a ramp).
If it's standardized container boxes, you're better off working with a crane type of lift/move/put system.

You only need vertical doors on the side(s) of starships if you either have a RAMP or you can make the craft "kneel" down on its landing gear to lay on its ventral bulkhead to minimize the elevation difference inside and outside the starship for loading/unloading operations.

However, if you're dealing with standardized modular containers (almost exclusively) ... and you have a small craft that travels WITH the starship ... you can use the small craft as a sky crane to load/unload those containers from your starship through the dorsal axis, rather than the horizontal. So you would have dorsal doors that open up and give access to the cargo boxes and your small craft "docks" with them for lifting out of and lowering into the cargo hold while the starship is "parked" on a world surface under gravity.

Key point here being that if you don't have a small craft that you can use for cargo marshaling logistics, you're probably better off with vertical axis doors on the side of the starship's hull and some sort of ramp/kneel arrangement.

The point of a container is load once unload once.

The gravitics/interstellar containers are optimized for "last parsec" deliveries.
If you need to use something else for "last klick" deliveries, there really ought to be an additional unload/load step involved anyway.

 

[spank]

This is where you're going to start running into issues of baseline assumptions ... and where those assumptions "come from" in order to generate constraints.

For example.
Why are multi-modal ISO shipping containers that size and shape? Why does the TEU have those dimensions?

I've thought about why shipping containers are the size and shape they are before, it largely comes down to the old "two horse's butts" which have influenced alot of Earth's transportation infrastructure. Here's an interesting article on why the boosters for the space shuttle were the size they were. It came down to ease of transport. They made them as big as they could and still transport them by rail. That in turn was determined by width height and width of the infrastructure the rail car would pass thru. And that inturn was effected by other historical factors, lead eventual back to the roman chariot, which was sized for two horses.

Space Exploration History: The Space Shuttle and the Horse's Rear End

A funny story about the sizing of the Space Shuttle

astrodigital.org

While the is not a direct a link and ridged a link as some people on the internet would have you believe, the influences are there. It is interesting that the Space Shuttle's SRBs, Zenit, Proton and the Falcon all come in at about 4 meters, seemingly all due to transportability.


Of course it's not a hard limitation, but once you get over a certain size you are going to have to build custom transportation solutions. Such as the Atlant, Super Guppy, or AN-225.

Myasishchev VM-T - Wikipedia

en.wikipedia.org

Interestingly the Super Guppy was derived from the B-29 Stratofortress, thru the B-50 then C-97. Here you can see the original fuselage, with the much larger structure grafted on to it. But in the end as impressive as it is, It is a custom low useage solution.


All of this is a long-winded way to say that sometimes function follows form, instead of the other way around. And while it's tempting to continue that trend upward it's also equally possible that a new transportation paradigm will emerge from Spacecraft. One not tethered to existing infrastructure. And that's the angle I'm coming at it from. Instead of developing freight handling from the ground up, I'm going from the sky down. Starting by considering what size the frieghtt is and then fitting the container to it, then building a transporter to work with the freight container. I started by

• What size are freight lots?
• What kind of unit is it measured in?
• What sort of area will it be expected to fit in?

We know that freight comes increments of 5 and 10 dTons, so the containers should come in those increments too. However, getting to the exact dimension of them is another matter. Ideally 4m X 3.5 m would give one dTon per meter, 4m x 3.5 m X 5m and 4m x 3m X 10m would give you 5 and 10 dTons. And one it's face that seems like a perfectly reasonable solution. 4 meters isn't that wide, 3 meters isn't that tall. If you are operating from grave vehicles you'll probably thru in a 4 meter by 4.5 meter profile, A bit larger and wider than Earth trucks and containers. But it's a "sky down" system. The transportation infrastructure will be built to accommodate the containers that the freight comes in.

However, we also have the entirely artificial and external constraint of the game. The game assumes a 1.5 meter grid, so we should try to work with that to make a container that fits the grid and work well within the game. The game makes the concession that 3m x 3m x 1.5m is a dTon, and while this is only 13.5 cubic meters instead of 14 cubic meters, this is a bit of a compromise but works well enough with the grid. But what size to make containers? There are several possibilities:


Staring with a 1.5 meter cube or 1 grid place, or 1/8th dTon and assuming 13.5 cubic meters per dTon,

• 2 x 2 or 3m X 3m gives .6666 dTons per meter or 1 dT per 1.5 Meters length
• 3 x 2 or 4.5m x 3m gives 1 dTon per meter or 1.5 dT per 1.5 meters length
• 3 x 2.5 or 4.5m x 3.75m gives 1.25 dTon per meter or 1.875 dT per 1.5 meters length
• 3 x 3 or 4.5m x 4.5m gives 1.5 dTon per meter or 2.25 dT per 1.5 meters length
• 3 x 3.5 or 4.5m x 5.25m gives 1.75 dTon per meter or 2.625 dT per 1.5 meters length
• 3.5 x 3.5 or 5.25 x 5.25m gives 2.0416 dTons per meter or 3.0625 dT per 1.5 meters length
• 4 x 4 or 6m X 6m gives 2.66 dTons per meter or 4 dT per 1.5 meters length

I think 6m by 6m is going to be the upper limit of our profiles, and that's stretching it a bit.

Using these I can make the following "standard" sized containers, Which I've rated by how well they fit in the grid and how cleanly they fall into meters lengths. I think these factors fall rank like this in importance:

1. How well the profile (width/height) fits the grid.
2. How well the containers dTon containers fit the grid
3. How well the containers divide into meters

With that in mind I did some calculating


From that three sizes stand out

1. 2 x 2 or 3m x 3m — fits the grid excellent and divides excellently into 5 and 10 dTon increments. - one container per grid square width
2. 2 x 2.5 or 3m x 3.75m — fits the grid well and divides excellently into 5 and 10 dTon increments. - 2 containers per 3 grid square width
3. 3 x 2.5 or 3.75 m x 3.75m — fits the grid ok and divides excellently into 5 and 10 dTon increments. - 3 containers per per grid square length

Based on that, I think the 3m X 3m profile is the best choice, of course YMMV.

 

[Spinward Flow]

• 10m x 5m x 2.8m = 140m3 = 10 tons
• 6.667 x 3.333 deck squares

If I wanted to make the dimensions more "deck plan friendly" for 1.5m grid squares, while keeping the 2L:1W ratio proportions to the form factor, I'd probably do something like this:

• 9.9m x 4.95m x 2.8m = 137.214m³ / 14 = 9.801 tons
• 6.6 x 3.3 deck squares

That way, the (starship) bulkhead walls enclosing the volume occupied by the box ought to be (adding +20cm to each dimension axis) 10.1m x 5.15m x 3m = 156.045m³ / 14 = 11.14607143 tons which is still within the +/- 10-20% tolerance we see canonically listed for the drawing of deck plans.



For reference, adding +20cm to the 10m x 5m x 2.8m = 140m3 = 10 tons dimension set for "clearance" into cargo holds yields 10.2m x 5.2m x 3m = 159.12m3 / 14 = 11.36571429 tons ... so still within the +/- 10-20% tolerance threshold for deck plans.

 

[spank]

Depends on if you're dealing with a homeworld standardization or a colony transplant context.

If it's a homeworld situation, then the infrastructure probably came first and the cargo form factors come along later to standardize a "fit" into that infrastructure.

If you're doing a "clean slate" colonization of another world (interplanetary and/or interstellar) then the form factors come first and the infrastructure gets built out as needed to support the colonization effort. This is why I maintain that because gravitics are TL=8 and jump drives are TL=9 (at least in CT), that means that ANY colony presence is probably going to START with gravitics for its transport logistics.

Now, it's perfectly possible for a colony world to "regress" to lower tech levels, either voluntarily or involuntarily ... but every interstellar transplant starts at TL=9+ minimum, meaning gravitics are available. Every "new" colony project starts from No Infrastructure available when dealing with a "pristine" world environment ... so might as well "start with gravitics" from the beginning. Eventually, as the population increases (to 7+) you'll probably start seeing other means of logistics transport aside from just gravitics emerge, but that's a "later on down the line" development for a colony that has survived startup and is prospering in its build out.

Depends on what you stuff into your cargo hold(s).
If it's just "loose" breakbulk occupying space, you can get away with pallets for stuff and drive forklifts around (and up/down a ramp).
If it's standardized container boxes, you're better off working with a crane type of lift/move/put system.

You only need vertical doors on the side(s) of starships if you either have a RAMP or you can make the craft "kneel" down on its landing gear to lay on its ventral bulkhead to minimize the elevation difference inside and outside the starship for loading/unloading operations.

However, if you're dealing with standardized modular containers (almost exclusively) ... and you have a small craft that travels WITH the starship ... you can use the small craft as a sky crane to load/unload those containers from your starship through the dorsal axis, rather than the horizontal. So you would have dorsal doors that open up and give access to the cargo boxes and your small craft "docks" with them for lifting out of and lowering into the cargo hold while the starship is "parked" on a world surface under gravity.

Key point here being that if you don't have a small craft that you can use for cargo marshaling logistics, you're probably better off with vertical axis doors on the side of the starship's hull and some sort of ramp/kneel arrangement.

The gravitics/interstellar containers are optimized for "last parsec" deliveries.
If you need to use something else for "last klick" deliveries, there really ought to be an additional unload/load step involved anyway.

The other thing to think about with cargo handling on spaceships is that for dedicated or semi-dedicated there will likely be some measure of built in cargo handling capability. On cargo aircraft for example there are either roller tracks the containers slide on or motorized rollers in the floor to move the containers automatically.



This is often mirrored in other links in the chain such as trucks and cargo docks.


I would assume space craft will have something similar, either rollers and powered rollers at lower TLs, or Grav lifters at higher TLs.
Of course at less developed places there's less "plane side" equipment to receive it. But even in the less developed regions of Earth they still get it done.



However in the very remote area there may be, as you've pointed out, No "planeside" cargo handling capability and it will be up to the crew of the ship to handle their own cargo. I think using an Air/Truck you could move the cargo from the Spaceship's handling system to the truck, and if necessary, Dollie. Once away from the spaceship it could be grabbed with a Grav/forklift, Grav/Crane (A top mount Grav Vehicle able to lift cargo from a truck) or other piece of handling equipment.
It would be slower, but do-able.





I assuming that a Grav Vehicle can't lift something that is directly under it's Gravcoils. If it can there's no reason to the crane needs to be as wide.
I also assuming you'd want two (or 4) for a 10 dTon container. It'd probably even be possible to use the Air/Truck as a hoist.

 

[RossWinn]

IMTU standard cargo containers are 2x2x5m or 4x4x5m.